pcm.c

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/*
 * PCM codecs
 * Copyright (c) 2001 Fabrice Bellard
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */
 
/**
 * @file
 * PCM codecs
 */
 
#include "config.h"
#include "config_components.h"
#include "libavutil/attributes.h"
#include "libavutil/float_dsp.h"
#include "libavutil/mem.h"
#include "libavutil/reverse.h"
#include "libavutil/thread.h"
#include "avcodec.h"
#include "bytestream.h"
#include "codec_internal.h"
#include "decode.h"
#include "encode.h"
#include "pcm_tablegen.h"
 
av_unused av_cold static int pcm_encode_init(AVCodecContext *avctx)
{
#if !CONFIG_HARDCODED_TABLES
    switch (avctx->codec->id) {
#if CONFIG_PCM_ALAW_ENCODER
    case AV_CODEC_ID_PCM_ALAW: {
        static AVOnce once_alaw = AV_ONCE_INIT;
        ff_thread_once(&once_alaw, pcm_alaw_tableinit);
        break;
    }
#endif
#if CONFIG_PCM_MULAW_ENCODER
    case AV_CODEC_ID_PCM_MULAW: {
        static AVOnce once_mulaw = AV_ONCE_INIT;
        ff_thread_once(&once_mulaw, pcm_ulaw_tableinit);
        break;
    }
#endif
#if CONFIG_PCM_VIDC_ENCODER
    case AV_CODEC_ID_PCM_VIDC: {
        static AVOnce once_vidc = AV_ONCE_INIT;
        ff_thread_once(&once_vidc, pcm_vidc_tableinit);
        break;
    }
#endif
    default:
        break;
    }
#endif
 
    avctx->bits_per_coded_sample = av_get_bits_per_sample(avctx->codec->id);
    avctx->block_align           = avctx->ch_layout.nb_channels * avctx->bits_per_coded_sample / 8;
    avctx->bit_rate              = avctx->block_align * 8LL * avctx->sample_rate;
 
    return 0;
}
 
/**
 * Write PCM samples macro
 * @param type   Datatype of native machine format
 * @param endian bytestream_put_xxx() suffix
 * @param src    Source pointer (variable name)
 * @param dst    Destination pointer (variable name)
 * @param n      Total number of samples (variable name)
 * @param shift  Bitshift (bits)
 * @param offset Sample value offset
 */
#define ENCODE(type, endian, src, dst, n, shift, offset)                \
    samples_ ## type = (const type *) src;                              \
    for (; n > 0; n--) {                                                \
        register type v = (*samples_ ## type++ >> shift) + offset;      \
        bytestream_put_ ## endian(&dst, v);                             \
    }
 
#define ENCODE_PLANAR(type, endian, dst, n, shift, offset)              \
    n /= avctx->ch_layout.nb_channels;                                  \
    for (c = 0; c < avctx->ch_layout.nb_channels; c++) {                \
        int i;                                                          \
        samples_ ## type = (const type *) frame->extended_data[c];      \
        for (i = n; i > 0; i--) {                                       \
            register type v = (*samples_ ## type++ >> shift) + offset;  \
            bytestream_put_ ## endian(&dst, v);                         \
        }                                                               \
    }
 
av_unused static int pcm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
                                      const AVFrame *frame, int *got_packet_ptr)
{
    int n, c, sample_size, ret;
    const short *samples;
    unsigned char *dst;
    const uint8_t *samples_uint8_t;
    const int16_t *samples_int16_t;
    const int32_t *samples_int32_t;
    const int64_t *samples_int64_t;
    const uint16_t *samples_uint16_t;
    const uint32_t *samples_uint32_t;
 
    sample_size = av_get_bits_per_sample(avctx->codec->id) / 8;
    n           = frame->nb_samples * avctx->ch_layout.nb_channels;
    samples     = (const short *)frame->data[0];
 
    if ((ret = ff_get_encode_buffer(avctx, avpkt, n * sample_size, 0)) < 0)
        return ret;
    dst = avpkt->data;
 
    switch (avctx->codec->id) {
    case AV_CODEC_ID_PCM_U32LE:
        ENCODE(uint32_t, le32, samples, dst, n, 0, 0x80000000)
        break;
    case AV_CODEC_ID_PCM_U32BE:
        ENCODE(uint32_t, be32, samples, dst, n, 0, 0x80000000)
        break;
    case AV_CODEC_ID_PCM_S24LE:
        ENCODE(int32_t, le24, samples, dst, n, 8, 0)
        break;
    case AV_CODEC_ID_PCM_S24LE_PLANAR:
        ENCODE_PLANAR(int32_t, le24, dst, n, 8, 0)
        break;
    case AV_CODEC_ID_PCM_S24BE:
        ENCODE(int32_t, be24, samples, dst, n, 8, 0)
        break;
    case AV_CODEC_ID_PCM_U24LE:
        ENCODE(uint32_t, le24, samples, dst, n, 8, 0x800000)
        break;
    case AV_CODEC_ID_PCM_U24BE:
        ENCODE(uint32_t, be24, samples, dst, n, 8, 0x800000)
        break;
    case AV_CODEC_ID_PCM_S24DAUD:
        for (; n > 0; n--) {
            uint32_t tmp = ff_reverse[(*samples >> 8) & 0xff] +
                           (ff_reverse[*samples & 0xff] << 8);
            tmp <<= 4; // sync flags would go here
            bytestream_put_be24(&dst, tmp);
            samples++;
        }
        break;
    case AV_CODEC_ID_PCM_U16LE:
        ENCODE(uint16_t, le16, samples, dst, n, 0, 0x8000)
        break;
    case AV_CODEC_ID_PCM_U16BE:
        ENCODE(uint16_t, be16, samples, dst, n, 0, 0x8000)
        break;
    case AV_CODEC_ID_PCM_S8:
        ENCODE(uint8_t, byte, samples, dst, n, 0, -128)
        break;
    case AV_CODEC_ID_PCM_S8_PLANAR:
        ENCODE_PLANAR(uint8_t, byte, dst, n, 0, -128)
        break;
#if HAVE_BIGENDIAN
    case AV_CODEC_ID_PCM_S64LE:
    case AV_CODEC_ID_PCM_F64LE:
        ENCODE(int64_t, le64, samples, dst, n, 0, 0)
        break;
    case AV_CODEC_ID_PCM_S32LE:
    case AV_CODEC_ID_PCM_F32LE:
        ENCODE(int32_t, le32, samples, dst, n, 0, 0)
        break;
    case AV_CODEC_ID_PCM_S32LE_PLANAR:
        ENCODE_PLANAR(int32_t, le32, dst, n, 0, 0)
        break;
    case AV_CODEC_ID_PCM_S16LE:
        ENCODE(int16_t, le16, samples, dst, n, 0, 0)
        break;
    case AV_CODEC_ID_PCM_S16LE_PLANAR:
        ENCODE_PLANAR(int16_t, le16, dst, n, 0, 0)
        break;
    case AV_CODEC_ID_PCM_F64BE:
    case AV_CODEC_ID_PCM_F32BE:
    case AV_CODEC_ID_PCM_S64BE:
    case AV_CODEC_ID_PCM_S32BE:
    case AV_CODEC_ID_PCM_S16BE:
#else
    case AV_CODEC_ID_PCM_S64BE:
    case AV_CODEC_ID_PCM_F64BE:
        ENCODE(int64_t, be64, samples, dst, n, 0, 0)
        break;
    case AV_CODEC_ID_PCM_F32BE:
    case AV_CODEC_ID_PCM_S32BE:
        ENCODE(int32_t, be32, samples, dst, n, 0, 0)
        break;
    case AV_CODEC_ID_PCM_S16BE:
        ENCODE(int16_t, be16, samples, dst, n, 0, 0)
        break;
    case AV_CODEC_ID_PCM_S16BE_PLANAR:
        ENCODE_PLANAR(int16_t, be16, dst, n, 0, 0)
        break;
    case AV_CODEC_ID_PCM_F64LE:
    case AV_CODEC_ID_PCM_F32LE:
    case AV_CODEC_ID_PCM_S64LE:
    case AV_CODEC_ID_PCM_S32LE:
    case AV_CODEC_ID_PCM_S16LE:
#endif /* HAVE_BIGENDIAN */
    case AV_CODEC_ID_PCM_U8:
        memcpy(dst, samples, n * sample_size);
        break;
#if HAVE_BIGENDIAN
    case AV_CODEC_ID_PCM_S16BE_PLANAR:
#else
    case AV_CODEC_ID_PCM_S16LE_PLANAR:
    case AV_CODEC_ID_PCM_S32LE_PLANAR:
#endif /* HAVE_BIGENDIAN */
        n /= avctx->ch_layout.nb_channels;
        for (c = 0; c < avctx->ch_layout.nb_channels; c++) {
            const uint8_t *src = frame->extended_data[c];
            bytestream_put_buffer(&dst, src, n * sample_size);
        }
        break;
#if CONFIG_PCM_ALAW_ENCODER
    case AV_CODEC_ID_PCM_ALAW:
        for (; n > 0; n--) {
            int v = *samples++;
            *dst++ = linear_to_alaw[(v + 32768) >> 2];
        }
        break;
#endif
#if CONFIG_PCM_MULAW_ENCODER
    case AV_CODEC_ID_PCM_MULAW:
        for (; n > 0; n--) {
            int v = *samples++;
            *dst++ = linear_to_ulaw[(v + 32768) >> 2];
        }
        break;
#endif
#if CONFIG_PCM_VIDC_ENCODER
    case AV_CODEC_ID_PCM_VIDC:
        for (; n > 0; n--) {
            int v = *samples++;
            *dst++ = linear_to_vidc[(v + 32768) >> 2];
        }
        break;
#endif
    default:
        return -1;
    }
 
    *got_packet_ptr = 1;
    return 0;
}
 
typedef struct PCMDecode {
    int sample_size;
} PCMDecode;
 
av_unused av_cold static int pcm_decode_init(AVCodecContext *avctx)
{
    PCMDecode *s = avctx->priv_data;
    static const struct {
        enum AVCodecID codec_id;
        int8_t sample_fmt;
        uint8_t sample_size;
        uint8_t bits_per_sample;
    } codec_id_to_samplefmt[] = {
    #define ENTRY(CODEC_ID, SAMPLE_FMT, BITS_PER_SAMPLE) \
        { AV_CODEC_ID_PCM_ ## CODEC_ID, AV_SAMPLE_FMT_ ## SAMPLE_FMT, \
        BITS_PER_SAMPLE / 8, BITS_PER_SAMPLE }
        ENTRY(S8, U8, 8),        ENTRY(S8_PLANAR, U8P, 8),
        ENTRY(S16BE, S16, 16),   ENTRY(S16BE_PLANAR, S16P, 16),
        ENTRY(S16LE, S16, 16),   ENTRY(S16LE_PLANAR, S16P, 16),
        ENTRY(S24DAUD, S16, 24), ENTRY(S24BE, S32, 24),
        ENTRY(S24LE, S32, 24),   ENTRY(S24LE_PLANAR, S32P, 24),
        ENTRY(S32BE, S32, 32),   ENTRY(S32LE, S32, 32),
        ENTRY(S32LE_PLANAR, S32P, 32),
        ENTRY(S64BE, S64, 64),   ENTRY(S64LE, S64, 64),
        ENTRY(SGA, U8, 8),       ENTRY(U8, U8, 8),
        ENTRY(U16BE, S16, 16),   ENTRY(U16LE, S16, 16),
        ENTRY(U24BE, S32, 24),   ENTRY(U24LE, S32, 24),
        ENTRY(U32BE, S32, 32),   ENTRY(U32LE, S32, 32),
        ENTRY(F32BE, FLT, 32),   ENTRY(F32LE, FLT, 32),
        ENTRY(F64BE, DBL, 64),   ENTRY(F64LE, DBL, 64),
        { .codec_id = AV_CODEC_ID_PCM_LXF, .sample_fmt = AV_SAMPLE_FMT_S32P, .sample_size = 5 },
    };
 
    for (unsigned i = 0; i < FF_ARRAY_ELEMS(codec_id_to_samplefmt); ++i) {
        if (codec_id_to_samplefmt[i].codec_id == avctx->codec_id) {
            s->sample_size    = codec_id_to_samplefmt[i].sample_size;
            avctx->sample_fmt = codec_id_to_samplefmt[i].sample_fmt;
            if (avctx->sample_fmt == AV_SAMPLE_FMT_S32)
                avctx->bits_per_raw_sample = codec_id_to_samplefmt[i].bits_per_sample;
            break;
        }
        av_assert1(i + 1 < FF_ARRAY_ELEMS(codec_id_to_samplefmt));
    }
 
    return 0;
}
 
typedef struct PCMScaleDecode {
    PCMDecode base;
    void (*vector_fmul_scalar)(float *dst, const float *src, float mul,
                               int len);
    float   scale;
} PCMScaleDecode;
 
av_unused av_cold static int pcm_scale_decode_init(AVCodecContext *avctx)
{
    PCMScaleDecode *s = avctx->priv_data;
    AVFloatDSPContext *fdsp;
 
    avctx->sample_fmt   = AV_SAMPLE_FMT_FLT;
    s->base.sample_size = 4;
 
    if (avctx->bits_per_coded_sample < 1 || avctx->bits_per_coded_sample > 24)
        return AVERROR_INVALIDDATA;
 
    s->scale = 1. / (1 << (avctx->bits_per_coded_sample - 1));
    fdsp = avpriv_float_dsp_alloc(0);
    if (!fdsp)
        return AVERROR(ENOMEM);
    s->vector_fmul_scalar = fdsp->vector_fmul_scalar;
    av_free(fdsp);
 
    return 0;
}
 
typedef struct PCMLUTDecode {
    PCMDecode base;
    int16_t   table[256];
} PCMLUTDecode;
 
av_unused av_cold static int pcm_lut_decode_init(AVCodecContext *avctx)
{
    PCMLUTDecode *s = avctx->priv_data;
 
    switch (avctx->codec_id) {
    default:
        av_unreachable("pcm_lut_decode_init() only used with alaw, mulaw and vidc");
#if CONFIG_PCM_ALAW_DECODER
    case AV_CODEC_ID_PCM_ALAW:
        for (int i = 0; i < 256; i++)
            s->table[i] = alaw2linear(i);
        break;
#endif
#if CONFIG_PCM_MULAW_DECODER
    case AV_CODEC_ID_PCM_MULAW:
        for (int i = 0; i < 256; i++)
            s->table[i] = ulaw2linear(i);
        break;
#endif
#if CONFIG_PCM_VIDC_DECODER
    case AV_CODEC_ID_PCM_VIDC:
        for (int i = 0; i < 256; i++)
            s->table[i] = vidc2linear(i);
        break;
#endif
    }
 
    avctx->sample_fmt = AV_SAMPLE_FMT_S16;
    s->base.sample_size = 1;
 
    return 0;
}
 
/**
 * Read PCM samples macro
 * @param size   Data size of native machine format
 * @param endian bytestream_get_xxx() endian suffix
 * @param src    Source pointer (variable name)
 * @param dst    Destination pointer (variable name)
 * @param n      Total number of samples (variable name)
 * @param shift  Bitshift (bits)
 * @param offset Sample value offset
 */
#define DECODE(size, endian, src, dst, n, shift, offset)                       \
    for (; n > 0; n--) {                                                       \
        uint ## size ## _t v = bytestream_get_ ## endian(&src);                \
        AV_WN ## size ## A(dst, (uint ## size ## _t)(v - offset) << shift);    \
        dst += size / 8;                                                       \
    }
 
#define DECODE_PLANAR(size, endian, src, dst, n, shift, offset)                \
    n /= channels;                                                             \
    for (c = 0; c < avctx->ch_layout.nb_channels; c++) {                       \
        int i;                                                                 \
        dst = frame->extended_data[c];                                         \
        for (i = n; i > 0; i--) {                                              \
            uint ## size ## _t v = bytestream_get_ ## endian(&src);            \
            AV_WN ## size ## A(dst, (uint ## size ##_t)(v - offset) << shift); \
            dst += size / 8;                                                   \
        }                                                                      \
    }
 
static int pcm_decode_frame(AVCodecContext *avctx, AVFrame *frame,
            int *got_frame_ptr, AVPacket *avpkt)
{
    const uint8_t *src = avpkt->data;
    int buf_size       = avpkt->size;
    PCMDecode *s       = avctx->priv_data;
    int channels       = avctx->ch_layout.nb_channels;
    int sample_size    = s->sample_size;
    int c, n, ret, samples_per_block;
    uint8_t *samples;
    int32_t *dst_int32_t;
 
    samples_per_block = 1;
    if (avctx->codec_id == AV_CODEC_ID_PCM_LXF) {
        /* we process 40-bit blocks per channel for LXF */
        samples_per_block = 2;
    }
 
    if (channels == 0) {
        av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n");
        return AVERROR(EINVAL);
    }
 
    if (avctx->codec_id != avctx->codec->id) {
        av_log(avctx, AV_LOG_ERROR, "codec ids mismatch\n");
        return AVERROR(EINVAL);
    }
 
    n = channels * sample_size;
 
    if (n && buf_size % n) {
        if (buf_size < n) {
            av_log(avctx, AV_LOG_ERROR,
                   "Invalid PCM packet, data has size %d but at least a size of %d was expected\n",
                   buf_size, n);
            return AVERROR_INVALIDDATA;
        } else
            buf_size -= buf_size % n;
    }
 
    n = buf_size / sample_size;
 
    /* get output buffer */
    frame->nb_samples = n * samples_per_block / channels;
    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
        return ret;
    samples = frame->data[0];
 
    switch (avctx->codec_id) {
    case AV_CODEC_ID_PCM_U32LE:
        DECODE(32, le32, src, samples, n, 0, 0x80000000)
        break;
    case AV_CODEC_ID_PCM_U32BE:
        DECODE(32, be32, src, samples, n, 0, 0x80000000)
        break;
    case AV_CODEC_ID_PCM_S24LE:
        DECODE(32, le24, src, samples, n, 8, 0)
        break;
    case AV_CODEC_ID_PCM_S24LE_PLANAR:
        DECODE_PLANAR(32, le24, src, samples, n, 8, 0);
        break;
    case AV_CODEC_ID_PCM_S24BE:
        DECODE(32, be24, src, samples, n, 8, 0)
        break;
    case AV_CODEC_ID_PCM_U24LE:
        DECODE(32, le24, src, samples, n, 8, 0x800000)
        break;
    case AV_CODEC_ID_PCM_U24BE:
        DECODE(32, be24, src, samples, n, 8, 0x800000)
        break;
    case AV_CODEC_ID_PCM_S24DAUD:
        for (; n > 0; n--) {
            uint32_t v = bytestream_get_be24(&src);
            v >>= 4; // sync flags are here
            AV_WN16A(samples, ff_reverse[(v >> 8) & 0xff] +
                             (ff_reverse[v        & 0xff] << 8));
            samples += 2;
        }
        break;
    case AV_CODEC_ID_PCM_U16LE:
        DECODE(16, le16, src, samples, n, 0, 0x8000)
        break;
    case AV_CODEC_ID_PCM_U16BE:
        DECODE(16, be16, src, samples, n, 0, 0x8000)
        break;
    case AV_CODEC_ID_PCM_S8:
        for (; n > 0; n--)
            *samples++ = *src++ + 128;
        break;
    case AV_CODEC_ID_PCM_SGA:
        for (; n > 0; n--) {
            int sign = *src >> 7;
            int magn = *src & 0x7f;
            *samples++ = sign ? 128 - magn : 128 + magn;
            src++;
        }
        break;
    case AV_CODEC_ID_PCM_S8_PLANAR:
        n /= avctx->ch_layout.nb_channels;
        for (c = 0; c < avctx->ch_layout.nb_channels; c++) {
            int i;
            samples = frame->extended_data[c];
            for (i = n; i > 0; i--)
                *samples++ = *src++ + 128;
        }
        break;
#if HAVE_BIGENDIAN
    case AV_CODEC_ID_PCM_S64LE:
    case AV_CODEC_ID_PCM_F64LE:
        DECODE(64, le64, src, samples, n, 0, 0)
        break;
    case AV_CODEC_ID_PCM_S32LE:
    case AV_CODEC_ID_PCM_F32LE:
    case AV_CODEC_ID_PCM_F24LE:
    case AV_CODEC_ID_PCM_F16LE:
        DECODE(32, le32, src, samples, n, 0, 0)
        break;
    case AV_CODEC_ID_PCM_S32LE_PLANAR:
        DECODE_PLANAR(32, le32, src, samples, n, 0, 0);
        break;
    case AV_CODEC_ID_PCM_S16LE:
        DECODE(16, le16, src, samples, n, 0, 0)
        break;
    case AV_CODEC_ID_PCM_S16LE_PLANAR:
        DECODE_PLANAR(16, le16, src, samples, n, 0, 0);
        break;
    case AV_CODEC_ID_PCM_F64BE:
    case AV_CODEC_ID_PCM_F32BE:
    case AV_CODEC_ID_PCM_S64BE:
    case AV_CODEC_ID_PCM_S32BE:
    case AV_CODEC_ID_PCM_S16BE:
#else
    case AV_CODEC_ID_PCM_S64BE:
    case AV_CODEC_ID_PCM_F64BE:
        DECODE(64, be64, src, samples, n, 0, 0)
        break;
    case AV_CODEC_ID_PCM_F32BE:
    case AV_CODEC_ID_PCM_S32BE:
        DECODE(32, be32, src, samples, n, 0, 0)
        break;
    case AV_CODEC_ID_PCM_S16BE:
        DECODE(16, be16, src, samples, n, 0, 0)
        break;
    case AV_CODEC_ID_PCM_S16BE_PLANAR:
        DECODE_PLANAR(16, be16, src, samples, n, 0, 0);
        break;
    case AV_CODEC_ID_PCM_F64LE:
    case AV_CODEC_ID_PCM_F32LE:
    case AV_CODEC_ID_PCM_F24LE:
    case AV_CODEC_ID_PCM_F16LE:
    case AV_CODEC_ID_PCM_S64LE:
    case AV_CODEC_ID_PCM_S32LE:
    case AV_CODEC_ID_PCM_S16LE:
#endif /* HAVE_BIGENDIAN */
    case AV_CODEC_ID_PCM_U8:
        memcpy(samples, src, n * sample_size);
        break;
#if HAVE_BIGENDIAN
    case AV_CODEC_ID_PCM_S16BE_PLANAR:
#else
    case AV_CODEC_ID_PCM_S16LE_PLANAR:
    case AV_CODEC_ID_PCM_S32LE_PLANAR:
#endif /* HAVE_BIGENDIAN */
        n /= avctx->ch_layout.nb_channels;
        for (c = 0; c < avctx->ch_layout.nb_channels; c++) {
            samples = frame->extended_data[c];
            bytestream_get_buffer(&src, samples, n * sample_size);
        }
        break;
#if CONFIG_PCM_ALAW_DECODER || CONFIG_PCM_MULAW_DECODER || \
    CONFIG_PCM_VIDC_DECODER
    case AV_CODEC_ID_PCM_ALAW:
    case AV_CODEC_ID_PCM_MULAW:
    case AV_CODEC_ID_PCM_VIDC: {
        const int16_t *const lut = ((PCMLUTDecode*)avctx->priv_data)->table;
        int16_t *restrict samples_16 = (int16_t*)samples;
 
        for (; n > 0; n--)
            *samples_16++ = lut[*src++];
        break;
    }
#endif
    case AV_CODEC_ID_PCM_LXF:
    {
        int i;
        n /= channels;
        for (c = 0; c < channels; c++) {
            dst_int32_t = (int32_t *)frame->extended_data[c];
            for (i = 0; i < n; i++) {
                // extract low 20 bits and expand to 32 bits
                *dst_int32_t++ =  ((uint32_t)src[2]<<28) |
                                  (src[1]         << 20) |
                                  (src[0]         << 12) |
                                 ((src[2] & 0x0F) <<  8) |
                                   src[1];
                // extract high 20 bits and expand to 32 bits
                *dst_int32_t++ =  ((uint32_t)src[4]<<24) |
                                  (src[3]         << 16) |
                                 ((src[2] & 0xF0) <<  8) |
                                  (src[4]         <<  4) |
                                  (src[3]         >>  4);
                src += 5;
            }
        }
        break;
    }
    default:
        return -1;
    }
 
    if (avctx->codec_id == AV_CODEC_ID_PCM_F16LE ||
        avctx->codec_id == AV_CODEC_ID_PCM_F24LE) {
        PCMScaleDecode *s2 = avctx->priv_data;
        s2->vector_fmul_scalar((float *)frame->extended_data[0],
                               (const float *)frame->extended_data[0],
                               s2->scale, FFALIGN(frame->nb_samples * avctx->ch_layout.nb_channels, 4));
    }
 
    *got_frame_ptr = 1;
 
    return buf_size;
}
 
#define PCM_ENCODER_0(id_, sample_fmt_, name_, long_name_)
#define PCM_ENCODER_1(id_, sample_fmt_, name_, long_name_)                  \
const FFCodec ff_ ## name_ ## _encoder = {                                  \
    .p.name       = #name_,                                                 \
    CODEC_LONG_NAME(long_name_),                                            \
    .p.type       = AVMEDIA_TYPE_AUDIO,                                     \
    .p.id         = id_,                                                    \
    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_VARIABLE_FRAME_SIZE | \
                      AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,                \
    .init         = pcm_encode_init,                                        \
    FF_CODEC_ENCODE_CB(pcm_encode_frame),                                   \
    CODEC_SAMPLEFMTS(sample_fmt_),                                          \
}
 
#define PCM_ENCODER_2(cf, id, sample_fmt, name, long_name)                  \
    PCM_ENCODER_ ## cf(id, sample_fmt, name, long_name)
#define PCM_ENCODER_3(cf, id, sample_fmt, name, long_name)                  \
    PCM_ENCODER_2(cf, id, sample_fmt, name, long_name)
#define PCM_ENCODER(id, sample_fmt, name, long_name)                        \
    PCM_ENCODER_3(CONFIG_PCM_ ## id ## _ENCODER, AV_CODEC_ID_PCM_ ## id,    \
                  AV_SAMPLE_FMT_ ## sample_fmt, pcm_ ## name, long_name)
 
#define PCM_DECODER_0(id, sample_fmt, name, long_name, Context, init_func)
#define PCM_DECODER_1(id_, sample_fmt, name_, long_name, Context, init_func)\
const FFCodec ff_ ## name_ ## _decoder = {                                  \
    .p.name         = #name_,                                               \
    CODEC_LONG_NAME(long_name),                                             \
    .p.type         = AVMEDIA_TYPE_AUDIO,                                   \
    .p.id           = id_,                                                  \
    .priv_data_size = sizeof(Context),                                      \
    .init           = init_func,                                            \
    FF_CODEC_DECODE_CB(pcm_decode_frame),                                    \
    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_PARAM_CHANGE,         \
}
 
#define PCM_DECODER_2(cf, id, sample_fmt, name, long_name, Context, init_func) \
    PCM_DECODER_ ## cf(id, sample_fmt, name, long_name, Context, init_func)
#define PCM_DECODER_3(cf, id, sample_fmt, name, long_name, Context, init_func) \
    PCM_DECODER_2(cf, id, sample_fmt, name, long_name, Context, init_func)
#define PCM_DEC_EXT(id, sample_fmt, name, long_name, Context, init_func)    \
    PCM_DECODER_3(CONFIG_PCM_ ## id ## _DECODER, AV_CODEC_ID_PCM_ ## id,    \
                  AV_SAMPLE_FMT_ ## sample_fmt, pcm_ ## name, long_name,    \
                  Context, init_func)
 
#define PCM_DECODER(id, sample_fmt, name, long_name)    \
    PCM_DEC_EXT(id, sample_fmt, name, long_name, PCMDecode, pcm_decode_init)
 
#define PCM_CODEC(id, sample_fmt_, name, long_name_)                    \
    PCM_ENCODER(id, sample_fmt_, name, long_name_);                     \
    PCM_DECODER(id, sample_fmt_, name, long_name_)
 
#define PCM_CODEC_EXT(id, sample_fmt, name, long_name, DecContext, dec_init_func) \
    PCM_DEC_EXT(id, sample_fmt, name, long_name, DecContext, dec_init_func);      \
    PCM_ENCODER(id, sample_fmt, name, long_name)
 
/* Note: Do not forget to add new entries to the Makefile and
 *       to the table in pcm_decode_init() as well. */
//            AV_CODEC_ID_*      pcm_* name
//                          AV_SAMPLE_FMT_*    long name                                DecodeContext   decode init func
PCM_CODEC_EXT(ALAW,         S16, alaw,         "PCM A-law / G.711 A-law",               PCMLUTDecode,   pcm_lut_decode_init);
PCM_DEC_EXT  (F16LE,        FLT, f16le,        "PCM 16.8 floating point little-endian", PCMScaleDecode, pcm_scale_decode_init);
PCM_DEC_EXT  (F24LE,        FLT, f24le,        "PCM 24.0 floating point little-endian", PCMScaleDecode, pcm_scale_decode_init);
PCM_CODEC    (F32BE,        FLT, f32be,        "PCM 32-bit floating point big-endian");
PCM_CODEC    (F32LE,        FLT, f32le,        "PCM 32-bit floating point little-endian");
PCM_CODEC    (F64BE,        DBL, f64be,        "PCM 64-bit floating point big-endian");
PCM_CODEC    (F64LE,        DBL, f64le,        "PCM 64-bit floating point little-endian");
PCM_DECODER  (LXF,          S32P,lxf,          "PCM signed 20-bit little-endian planar");
PCM_CODEC_EXT(MULAW,        S16, mulaw,        "PCM mu-law / G.711 mu-law",             PCMLUTDecode,   pcm_lut_decode_init);
PCM_CODEC    (S8,           U8,  s8,           "PCM signed 8-bit");
PCM_CODEC    (S8_PLANAR,    U8P, s8_planar,    "PCM signed 8-bit planar");
PCM_CODEC    (S16BE,        S16, s16be,        "PCM signed 16-bit big-endian");
PCM_CODEC    (S16BE_PLANAR, S16P,s16be_planar, "PCM signed 16-bit big-endian planar");
PCM_CODEC    (S16LE,        S16, s16le,        "PCM signed 16-bit little-endian");
PCM_CODEC    (S16LE_PLANAR, S16P,s16le_planar, "PCM signed 16-bit little-endian planar");
PCM_CODEC    (S24BE,        S32, s24be,        "PCM signed 24-bit big-endian");
PCM_CODEC    (S24DAUD,      S16, s24daud,      "PCM D-Cinema audio signed 24-bit");
PCM_CODEC    (S24LE,        S32, s24le,        "PCM signed 24-bit little-endian");
PCM_CODEC    (S24LE_PLANAR, S32P,s24le_planar, "PCM signed 24-bit little-endian planar");
PCM_CODEC    (S32BE,        S32, s32be,        "PCM signed 32-bit big-endian");
PCM_CODEC    (S32LE,        S32, s32le,        "PCM signed 32-bit little-endian");
PCM_CODEC    (S32LE_PLANAR, S32P,s32le_planar, "PCM signed 32-bit little-endian planar");
PCM_CODEC    (U8,           U8,  u8,           "PCM unsigned 8-bit");
PCM_CODEC    (U16BE,        S16, u16be,        "PCM unsigned 16-bit big-endian");
PCM_CODEC    (U16LE,        S16, u16le,        "PCM unsigned 16-bit little-endian");
PCM_CODEC    (U24BE,        S32, u24be,        "PCM unsigned 24-bit big-endian");
PCM_CODEC    (U24LE,        S32, u24le,        "PCM unsigned 24-bit little-endian");
PCM_CODEC    (U32BE,        S32, u32be,        "PCM unsigned 32-bit big-endian");
PCM_CODEC    (U32LE,        S32, u32le,        "PCM unsigned 32-bit little-endian");
PCM_CODEC    (S64BE,        S64, s64be,        "PCM signed 64-bit big-endian");
PCM_CODEC    (S64LE,        S64, s64le,        "PCM signed 64-bit little-endian");
PCM_CODEC_EXT(VIDC,         S16, vidc,         "PCM Archimedes VIDC",                   PCMLUTDecode,   pcm_lut_decode_init);
PCM_DECODER  (SGA,          U8,  sga,          "PCM SGA");